This invention is generally directed to toner and developer compositions, and more specifically, the present invention is directed to developer and toner compositions containing certain polyester imide resins, such as those derived from JEFFAMINE.TM., and a dianhydride, such as 1,3-bis-(1',2'-anhydro-4'-trimellitate)-2-acetoxypropane or mixture of about 80 to about 98 percent by weight of dianhydride, and about 2 to about 20 weight percent of trianhydride, such as 1,2,3-tris-(1',2'-anhydro-4'-trimellitate)-propane, and process for the preparation of polyester imide resins thereof. In embodiments, there are provided in accordance with the present invention, low cost, low melting and excellent vinyl offset toner compositions comprised of certain polyester imide amine resins obtained, for example, by melt condensation processes, and pigment particles comprised of, for example, carbon black, magnetites, or mixtures thereof, thereby providing for the development and generation of black and/or colored images. In embodiments, there are provided in accordance with the present invention polyester imide resins of the following formula ##STR2## and in embodiments wherein X is a mixture containing from about 80 mole percent to about 98 mole percent of an acetyl group and from about 2 mole percent to about 20 mole percent of trimellitimide branching group; n represents the number of repeating segments and can be a number of from about 10 to about 1,000; and R is an aliphatic component such as alkylene, oxyalkylene or polyoxyalkylene. The toner compositions of the present invention in embodiments possess a number of advantages including exceptional nonvinyl resistance, low fixing characteristics such as from about 125.degree. C. to about 145.degree. C., deinking characteristics, excellent blocking characteristics, such as from about 55.degree. C. to about 65.degree. C., and low relative humidity sensitivities. The polyester imides of the present invention can in embodiments be generated by the reaction of a dianhydride, such as 1,3-bis-(1', 2'-anhydro-4'-trimellitate)-2'-acetoxypropane available as AC-32.TM. from Anhydride and Chemicals Incorporated, or a mixture of the aforementioned dianhydride and trianhydride such as 1,2,3-tris-(1', 2'-anhydro-4'-trimellitate)-propane and, such mixtures being available as AC-3205.TM. from Anhydride and Chemicals Incorporated, and believed to be of the following formula with a molecular weight equivalent of from about 482 grams per mole to about 614 grams per mole ##STR3## with a diamino terminated alkylene, such as an aliphatic diamines, oxyalkylene or polyoxy alkylene, such as JEFFAMINES.TM. available from Texaco Chemicals as JEFFAMINE D-230.TM., D-400.TM., D-700.TM., EDR-148.TM., EDR-192.TM. and believed to be of the following formula, or aliphatic diamines like DYTEK.TM.
______________________________________ ##STR4## wherin ______________________________________ EDR-148 .TM. n = 2; R = H EDR-192 .TM. n = 3; R = H D-230 .TM. n = 2 or 3; R = CH.sub.3 D-400 .TM. n = 5 or 6; R = CH.sub.3 ______________________________________
The aforementioned polyester imides exhibit in embodiments a number average molecular weight of from about 2,500 grams per mole to about 100,000 grams per mole as measured by vapor phase osmometry, have a glass transition temperature of from about 45.degree. C. to about 65.degree. C., and more preferably of from about 50.degree. C. to about 65.degree. C. as measured by the Differential Scanning Calorimeter, low fixing characteristics, such as from about 125.degree. C. to about 145.degree. C., and rapid jetting characteristics, such as rates of from about 0.90 to about 2.2 relative to poly(propoxylated bisphenol A) toner resins, and a M.sub.w of from about 1,500 to about 20,000.
Toners with the polyester imides of the present invention possess low melt fusing temperatures, for example 28.degree. C. lower than certain styrene based toners, such as the Xerox Corporation 1075, which can exhibit a broad fusing latitude of about 50.degree. C., and also the polyester imide polymer of the present invention has excellent vinyl offset resistance.
The transfer of toner from xerographic images to plasticized polyvinylchloride (PVC) notebook covers has been a problem since, for example, severe damage caused to the hardcopy. This phenomenon is commonly referred to as vinyl offset and is related to the diffusion of plasticizer from the vinyl into the toner resin. Vinyl offset is measured by the following method. A plain sheet of paper is placed under the clear vinyl sample to provide a good contrast. The image of a single frame of the sample covering approximately a 9 millimeter square area is captured in a full color frame of the video processing board. This full color image is then converted into a gray scale image by adjusting its RGB components. An intensity histogram of this gray scale image is performed and a threshold intensity level is determined. This step totally eliminates subjective judgment by the operator. All pixels with intensities below the threshold level are considered to represent offset toner. Conversely, all pixels above the threshold level are considered to represent clear vinyl. For clarity, pixels representing offset toner are displayed in black and pixels representing clear vinyl are displayed in red. The number of pixels representing the vinyl offset is then determined for each frame. The vinyl offset for a single frame is calculated using the following formula EQU Vinyl offset=(Offset Pixels/Total Pixels).times.100% (1)
The entire sample is scanned frame-by-frame and the vinyl offset is obtained by taking the average over all frames. For example, in the case of severe offset, where all the toner transfers onto PVC, the vinyl offset is recorded as 100 percent. On the other hand, in the case where no toner transfers to the PVC the vinyl offset is recorded as 0 percent as calculated by Equation (1).
The type of plasticizer used in the PVC affects vinyl offset, however, the major components appear to be the polymeric structure of the toner resin and molecular weight. For example, styrene-butylmethacrylate toner exhibits severe vinyl offset, such as from about 85 to 95 percent, whereas the styrene-butadiene based toner resins exhibit a much lower degree of vinyl offset, such as from about 0.3 to about 0.9 percent. It should be noted that even though the vinyl offset value is small for the styrene-butadiene based toner images, this level of offset is still visible to the naked eye. There is, therefore, a need for toner images wherein no vinyl offset results, and wherein there is specifically a vinyl offset of 0 percent as calculated by Equation (1). In addition, there is a need for toners to display in addition to 0 percent vinyl offset, low fixing temperature of from about 120.degree. C. to about 140.degree. C., with a fusing latitude of from about 20.degree. C. to about 60.degree. C., and which exhibits low relative humidity sensitivity, such as from about 1.0 to about 2.9, and wherein matte images are obtained, such as from about 0 gloss units to about 20 gloss units, as measured by the Gardner gloss metering unit.
A number of toner resins are known, such as styrene acrylates, styrene methacrylates, styrene butadiene, polyesters, polyamides, and the like.
Certain polyimide resins and, more specifically, liquid crystalline polyimide resins are known such as summarized and illustrated in the Encyclopedia of Polymer Science and Engineering, 2nd Edition, Volume No. 12, published by Wiley (1985). However, such polyimide resins are aromatic and useful as high performance materials, there being no disclosure for use as toners.
Thermotropic liquid crystalline polyimides are illustrated in U.S. Pat. No. 5,348,830, the disclosure of which is wholly incorporated herein by reference, which discloses toner and developer compositions with thermotropic liquid crystalline polyimides. The polyester imide resins of this invention differ in that, for example, they do not exhibit liquid crystalline properties, and moreover are of substantially lower cost such as from about 80 percent to about 500 percent less than the liquid crystalline polyimides of U.S. Pat. No. 5,348,830 as estimated, for example, from the Chemical Marketing Reporter (1993 issue).
Illustrated in the following copending applications, the disclosures of each being totally incorporated herein by reference, are:
U.S. Ser. No. 144,075, illustrates a toner composition comprised of a pigment and a crosslinked polyimide, and wherein the crosslinked polyimide can be obtained from the reaction of a peroxide with an unsaturated polyimide of the formula ##STR5## wherein X is ##STR6## R is alkyl or oxyalkylene; and m represents the number of monomer segments present and is a number of from about 10 to about 1000.
U.S. Pat. No. 5,348,831, illustrates a toner composition comprised of pigment, and a polyester imide resin of the formula ##STR7## wherein n represents the number of segments present and is a number of from about 10 to about 10,000; R' is alkyl or alkylene; and R is independently selected from the group consisting of an oxyalkylene and polyoxyalkylene. Note that R' is a difunctional moiety and derived from a diol, and this differs in that the polyester imide of this invention is represented by a trifunctional moiety linked via ester groups and derived from a triol, hence providing the resin with the ability of branching and leading to broader polydispersity resin useful for matte toner applications with enhanced vinyl offset properties.
U.S. Ser. No. 144,918, illustrates a toner composition comprised of pigment, and polyimide of the formula ##STR8## wherein m represents the number of monomer segments present; X is ##STR9## thus X can be benzophenone, oxydiphthalic, hexafluoropropane diphenyl, diphenyl sulfone, or biphenyl; X is attached to four imide carbonyl moieties; and R is independently selected from the group consisting of alkylene, oxyalkylene and polyoxyalkylene.
U.S. Ser. No. 144,956, illustrates a toner composition comprised of pigment, and polyimide of the formula ##STR10## wherein n represents the number of monomer segments, and is a number of from about 10 to about 1,000; and R is alkylene, oxyalkylene, or polyoxyalkylene.
Furthermore, there are also disclosed in copending applications U.S. Ser. No. 221,956 and U.S. Ser. No. 251,161 polyimide toner resins with deinkable characteristics. More specifically, copending application U.S. Ser. No. 221,956 discloses a toner comprised of pigment, and a polyimide-imine resin of the formula ##STR11## wherein m and n represent the number of monomer segments; X is independently selected from the group consisting of a tetravalent aromatic, polyarylomatic or cycloaliphatic group with from about 6 to about 20 carbon atoms and a cycloaliphatic group; R is independently selected from the group consisting of alkylene, oxyalkylene and polyoxyalkylene; and R' is independently selected from the group consisting of alkyl, alkylene and arylene; and U.S. Ser. No. 251,161 discloses a toner composition comprised of pigment, and a polyimide of the formulas ##STR12## wherein n represents the number of monomer segments, and R is alkylene, oxyalkylene or polyoxyalkylene. The polyester imide of this invention displays 0 percent vinyl offset as calculated by Equation (1).
The disclosures of each of the copending patent applications mentioned herein are totally incorporated herein by reference.